I wondered that too, but I cannot affect it in any way. It disappears when I go to air ride menu so I doubt it. It is just a thin, unlabeled LCD "thermometer" type indicator. mine currently indicates 1/2 scale but I've seen pictures of others showing nearly full scale. I'm dashed!
Could it be a "time between service" then how is it reset?

The red and white part of lines are made on screen. When the bike is "on", that's when see fuel and temp gages. When pressing air buttons to check frt or rear psi in neutral, then air pressure gage comes up. Mine has nothing (no gage) to right of temp. If what you are asking is what is that dark line … it's a "graphic" aid to show acceptable or normal range. I goes away with gage as it's not used when checking air in shocks / etc. As long as the stack of blocks end in the range beside the black line, temp is OK.

I look forward to hearing from you. So far, only opinions and guesses. I would love to see what an actual owners manual or service manual says about this Gage what it is attached to whether it’s a computer function or what. I suspected it was a “Time for service“ Indicator as different pictures from different bikes show different positions and indications. I can’t believe the operating temperature would be different from bike to bike. Sorry to be so stubborn but I just gotta know.

It doesn't move, change, or do anything else. It's just like the scale on the left side for the fuel - all it does is turn on when the bike turns on, to show a scale that indicates "higher than here is hot."

So it comes on when the bike is on, and goes away when the bike is off. No additional functionality beyond that.

It doesn't move, change, or do anything else. It's just like the scale on the left side for the fuel - all it does is turn on when the bike turns on, to show a scale that indicates "higher than here is hot."

So it comes on when the bike is on, and goes away when the bike is off. No additional functionality beyond that.

Wot he said. You are reading something into the graphic that simply isn't there the owners manual has no reference to it other than explain temp is shown in bars to the left

It doesn't move, change, or do anything else. It's just like the scale on the left side for the fuel - all it does is turn on when the bike turns on, to show a scale that indicates "higher than here is hot."

So it comes on when the bike is on, and goes away when the bike is off. No additional functionality beyond that.

Wot he said. You are reading something into the graphic that simply isn't there the owners manual has no reference to it other than explain temp is shown in bars to the left

Page 17 in mine. It's purpose is to indicate mechanical safety range of coolant temp. It goes away when you check air suspension pressures.